I have traveled to something like 80 countries now and have used all sorts of bags both nylon, leather and aluminum. At the end of the day everyone who travels to the ends of the earth ends up with a nylon bag. They are lighter and more durable than leather. Buy an Osprey and don't look back. I was on a boat ride in Patagonia recently and over half the luggage was Osprey, and the rest was a mix of high end north face duffels and some Patagonia duffles.